Role of Nb 3Si in high temperature deformation of a cast Nb - 10 a/o Si in-situ composite

Abstract

This paper reports on intermetallic compounds based on refractory metals such as Nb, Mo, and W which possess properties conducive to high temperature applications. Many of these intermetallics have very high melting points and retain their strength and stiffness to a high temperature. A serious impediment to the application of these materials is their low room temperature fracture toughness. A viable solution to this problem is to form in-situ composites of a brittle intermetallic compound and metallic phase. Room temperature toughness is improved in such composites by the ductile phase ligaments bridging cracks. However, since the deformation of the continuous phase controls the overall deformation behavior of the composite, the role of the intermetallic matrix is also important, especially at temperatures where the intermetallic phase undergoes plastic deformation.